feat(process): have proper error message when process is failing

[tony-go]

Current behavior

When a user passes a wrong command, it will fail silently.

const scenario = clix('command that fail')
    .expect('poof').
    
const { ok } = await scenario.run();

// the run doesn't throw 😱
// ok === false

Expected behavior

const scenario = clix('command-foo')
    .expect('poof').
 
try {
    const { ok } = await scenario.run();
} catch (e) {
    // .run() should we should catch an error
    // e === new Error('Run command-foo failed: <error>');
}